Where did the muon neutrinos go?
The Main Injector Neutrino Oscillation Search collaboration at DOE’s Fermilab has presented new neutrino disappearance results that are consistent with neutrino oscillation. In this case, muon neutrinos can change into tau neutrinos or electron neutrinos, which can then escape detection by the 6,000-ton MINOS far detector. Sending a high-intensity beam of muon neutrinos from Fermilab about 450 miles through the earth to a neutrino detector in the Soudan Underground Laboratory in Minnesota, the MINOS collaboration observed the disappearance of about half of the neutrinos. Without neutrino oscillation, the MINOS far detector would have recorded about 336 muon neutrinos. Instead, the collaboration observed 215 muon neutrinos. With high precision and a large data sample over the next few years, MINOS will pave the way to a better understanding of neutrino oscillations.
